While the holidays are quiet for me, there are some really busy times in my profession too. They are not even planned; they just happen and then it goes on for about a week or so without a break. During one of those episodes, I told my employer they should be subsidizing my intake of liquor.

Anyway, the best way to get through it, I've found, is through meditation.
Also, it may sound strange, but take some time to do the following about four or five times a day, about ten times each session... Hold the right nostril closed and breathe in deep through the left nostril. Then hold the left nostril and let the air out the right one. After about five of those, do the same, but with the air going in the right nostril and out the left. It's a yoga meditation thing and, for some odd reason, is very calming (to me, at least).